CPC A61B 5/4818 (2013.01) [A61B 5/0002 (2013.01); A61B 5/02007 (2013.01); A61B 5/02427 (2013.01); A61B 5/6832 (2013.01)] | 21 Claims |
1. A system configured to diagnose sleep comprising an apparatus configured to be attached to a patient, the apparatus comprising:
an optical sensor configured to measure a blood volume pulse of the patient;
a wireless communication interface configured to wirelessly transmit data representing the measured blood volume pulse; and
wherein the system further comprises one or more processors configured to:
obtain the wirelessly transmitted data representing the measured blood volume pulse;
derive, by processing the data representing the measured blood volume pulse, a signal that represents peripheral arterial tone, wherein the derivation comprises:
determining an upper envelope of the measured blood volume pulse and a lower envelope of the measured blood volume pulse, wherein the upper envelope is a smoothed curve connecting peaks of the measured blood volume pulse and the lower envelope is a smoothed curve connecting troughs of the measured blood volume pulse, and
calculating the signal that represents peripheral arterial tone based on a difference between the upper envelope and the lower envelope; and
determine occurrences of sleep events from changes in the derived peripheral arterial tone signal,
diagnose the sleep of the patient based on the determined occurrences of sleep events.
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